¶ 1. In Hawkes v. Spence we addressed the “seemingly irreconcilable conflict” that arises when a “custodial parent’s interest in building a new life with the children” in a distant location is “pitted against the noncustodial parent’s interest in maintaining a close relationship with the children.” 2005 VT 57, ¶ 1, 178 Vt. 161, 878 A.2d 273. While acknowledging that “there is no precise formula” for resolving such conflicts, we adopted a governing standard and a nonexclusive list of relevant factors that trial courts must apply in determining whether a reexamination of parental rights and responsibilities in such circumstances is justified. Id. ¶ 13. Here, we are confronted with yet another difficult relocation dispute between two loving, capable parents, both of whom are intent on maintaining their current contact with the child, yet only one of whom can prevail. Such cases underscore yet again that this area of the law is not susceptible to precise formulas, and that we must permit trial courts — guided by the principles set forth in Hawkes — the latitude to exercise their discretion to reach reasonable decisions. As explained more fully below, that is what occurred here. Accordingly, we affirm the judgment.
*487¶ 2. The record evidence may be summarized as follows. The parties were married in 1996 and divorced in October 2003. They have two children who were approximately three years old and fourteen months old at the time of the parties’ separation in October 2002, and six and four years old at the time of the proceedings below. The divorce judgment incorporated a stipulation between the parties granting mother sole physical rights and responsibilities and providing for shared legal rights and responsibilities. The judgment also accorded father substantial parent-child contact. In addition to visitation every other weekend from Friday until Monday evening, and off-weeks from Tuesday until Wednesday evening, it authorized father to pick the children up from daycare on a daily basis and bring them to mother’s home, where he cared for them until she arrived from work. In addition, father testified, and the court found, that father made considerable efforts to see the children on other occasions, staying with neighbors and friends near the marital home (which father had conveyed to mother pursuant to the divorce stipulation), and spending time with the children during days off from his job as a police officer with the Stowe Police Department.
¶ 3. Father testified, and the court found, that mother’s job as the comptroller of a company in Burlington made it difficult for her to arrive home until after 6:00 p.m., which in turn made it impossible for father to pick up the children daily from daycare and arrive for his police shift on time. Father advised that he could no longer do the daily pickups. As a result, in June 2004, mother moved from Morrisville to Vergennes to shorten her commute time. Thereafter, father’s time with the children decreased. According to mother, this was because father no longer wished to exercise all of his visitation rights, while father contended that mother denied him visitation. Finding mother’s excuse incredible for denying father’s Thanksgiving visit so she could take the children to see her boyfriend’s parents in Michigan, the court further found it was mother, and not father, who initiated the lapse in father’s visitation.
¶ 4. In November 2004, mother informed father that she intended to remarry and move with the children and her new husband, an Army sergeant then stationed in Vermont, to North Carolina. Father subsequently moved to modify custody based on mother’s move to Vergennes and the disruptions that this had occasioned in the children’s lives, including a change of daycare providers and reduced contact with father and his family, as well as on mother’s contemplated move to North Carolina. Mother, in response, filed a cross-motion to *488modify custody and parent-child contact, seeking sole legal rights and responsibilities and a new visitation schedule. In a supporting affidavit, mother denied she was considering a move to North Carolina, stating that her new husband “has no orders at present to be transferred to anywhere let alone North Carolina.” Mother later filed an amended motion and supplemental affidavit, indicating that her husband’s replacement had arrived in Vermont and it was expected that within about 30 days her husband would receive orders to report to a new duty station outside Vermont, possibly in the states of North Carolina, Colorado, or Washington. As to mother’s earlier affidavit purporting ignorance about any orders requiring her husband to move, the court found that mother, contrary to her sworn declaration, was then aware that her husband had standing orders to leave Vermont and relocate within nine months at the latest.
¶ 5. An evidentiary hearing on the cross-motions was held in August 2005. Shortly thereafter, the court issued a written decision, concluding that mother’s proposed relocation represented a real, substantial, and unanticipated change of circumstances justifying a reexamination of parental rights and responsibilities under 15 V.S.A § 668, and that, under the criteria set forth in 15 V.S.A. § 665, the best interests of the children favored an award of sole physical and legal rights and responsibilities to father. In addressing the threshold question of changed circumstances, the court recognized that the issue was governed by the principles set forth in Hawkes v. Spence. There, we held that “relocation is a substantial change of circumstances justifying a reexamination of parental rights and responsibilities only when the relocation significantly impairs either parent’s ability to exercise responsibilities the parent has been exercising or attempting to exercise under the parenting plan.” Hawkes, 2005 VT 57, ¶ 13 (quotation and citation omitted).
¶ 6. Hawkes explained that in determining whether a parent’s exercise of responsibilities will be substantially impaired, the court may consider, among other factors, “[t]he amount of custodial responsibility each parent has been exercising and for how long, the distance of the move and its duration, and the availability of alternative visitation arrangements.” Id. (quotation and citation omitted). Additionally, “the court should consider the amount of custodial responsibility that a parent has been actually exercising, rather than the amount allocated but not necessarily exercised under a court order.” Id. (quotation and citation omitted) (emphasis added).
*489¶ 7. The trial court here systematically considered each of the foregoing factors. As to custodial time, the court found that, although mother had been granted sole physical rights and responsibilities, father had “maximized his contact with the children such that he had them in his care almost as much as [mother].” Next, the court found that the distance and duration of mother’s proposed move to a military posting out of state were extensive, and would substantially affect the children’s ability to maintain their current relationship with father and his family in Vermont. Finally, the court found that mother’s proposed summer and holiday visitation schedule with father would significantly diminish his contact with the children and “negatively impact their relationship.” Indeed, given its findings that mother previously denied father’s visitation rights, the court justifiably expressed “some concerns that a[n alternative] visitation order would not be adhered to by [mother].”
¶ 8. The court thus determined that “[e]ach of the Hawkes factors, as well as many others, support the court’s conclusion that the proposed relocation is a real, substantial and unanticipated change in circumstances requiring the court to consider whether modification of the parties’ parental rights and responsibilities is appropriate.” Turning to that question, the court remarked that father bore “a heavy burden of proof,” presumably in reference to the “high hurdle” faced by a noncustodial parent “in justifying the violent dislocation of a change in custody from one parent to the other” when the change is “based solely on the custodial parent’s decision to relocate.” Hawkes, 2005 VT 57, ¶ 11. “On the other hand,” the court correctly observed from Hawkes, “when childrearing and its concomitant decision-making are shared, relocation to a remote location by one parent requires at the very least a reassessment of the custodial arrangement and, because of the practicalities involved in shared parenting, will often necessitate a change in custody.” Id. ¶ 12. The court also noted that father’s motion was not based solely on the proposed relocation, but also on a general breakdown in the parties’ relationship, mother’s interference with father’s visitation and a concern that the children would continue to move every three years if left in mother’s physical custody.
¶ 9. Proceeding to apply the factors of 15 V.S.A. § 665(b), the court found both parents were close to the children and were able to provide them with love, affection, and guidance, as well as a safe and nurturing environment, and that these factors were therefore evenly balanced. The court placed considerable emphasis, however, on the criterion addressed to the children’s adjustment to their home, school, and *490community — particularly in Morrisville where they had lived near father prior to the move, attended day care, and been surrounded by friends and family. The court noted father planned to live in Morrisville, where the children could resume their schooling and relationships with friends, neighbors, and family. The court found that this factor weighed heavily in favor of a change of custody to father.
¶ 10. The court found neither parent particularly able to foster a positive relationship with the other. Nevertheless, the court expressed concern that mother had not been straightforward with father or the court about her future plans, had not cooperated with father’s visitation rights in the past and was more likely than father to expose the children to disputes between the parents and alienation from the other parent. In contrast, the court found that father was more likely to follow an order granting mother substantial visitation, and was less likely than mother to disparage, or alienate the children from, the other parent.
¶ 11. Consistent with its finding that the children were strongly attached to their home and community, the court also found that they enjoyed “strong, beneficial relationships with family and friends in Vermont” that would be damaged by a relocation out of state. While acknowledging the “positive force” of their new relationship with mother’s husband and his young daughter, the court concluded that it did not outweigh the children’s relationship with father and other family members and friends in Vermont, and that this factor also favored an award of sole custody to father.
¶ 12. As for the children’s relationship with their primary care provider, the court recognized that mother capably fulfilled this role and that the children would not benefit from a disruption of this relationship — a circumstance which led the court to describe this as a “most troubling” and “difficult case.” Noting that father could also fill the role of primary caretaker, and had “approximated” that role in the past, the court explained that this factor weighed heavily in mother’s favor, but was counterbalanced by other factors. The court determined that, despite mother’s status as primary caretaker, the expected repeated moves of the children and lost contact with father were unacceptable consequences of mother’s decision to move only to follow her new spouse’s career. The dissent perceives this characterization as trivializing and devaluing mother’s choice to support her spouse’s career, post, ¶ 45, when the family court clearly considered this motive, not in isolation, but weighed against the reasonably anticipated constriction, if not foreclosure, by mother of the children’s contact with father. The *491family court found mother’s rationale less compelling than the sacrifice of the children’s relationship with their father.
¶ 13. On balance, the court concluded that an award of sole legal and physical rights and responsibilities to father was “most likely to preserve the children’s relationship with both of their parents and afford them the greatest amount of stability and security,” and therefore served the best interests of the children. The court awarded mother substantial parent-child contact, including every school vacation during the school year in excess of three days, eight consecutive weeks during the summer, one weekend per month in Vermont, and unlimited telephone contact. The court denied mother’s subsequent motion for reconsideration and stay. This appeal followed.
¶ 14. Mother raises a number of claims, which she has grouped under three broad headings. Under the first, she contends the court misapplied the Hatches factors in concluding that a relocation would significantly impair father’s exercise of custodial responsibilities. She claims, in this regard, that the court impermissibly lowered the standard for a change of custody from the primary care provider. The claim is premised on mother’s assertion that, in calculating the overall amount of custodial responsibility exercised by father, the court miseharaeter-ized father’s involvement with the children as nearly equivalent to that of mother. She argues that the quantity of father’s contact with the children, which the court found to be approximately twelve out of fourteen days prior to mother’s move to Vergennes, was not equivalent to the quality of her daily involvement as the primary care provider.
¶ 15. We will not disturb the family court’s factual findings unless, viewing the evidence in the light most favorable to the judgment and excluding the effect of modifying evidence, there is no credible evidence to support them. Sochin v. Sochin, 2004 VT 85, ¶ 10, 177 Vt. 540, 861 A.2d 1089 (mem.). Father testified that he engaged in extensive activities with the children while they were in his care, including playing, coloring, going on outings, reading stories at bedtime, and shopping.1 He also testified without dispute that he had taken care of the children for consecutive periods of over a week at a time. The parties’ friend and former neighbor in Morrisville described *492father as “Mr. Mom” and “an exceptional father,” observing that he had “spent a tremendous amount of time with the kids and did a lot of stuff with them and took care of them and nurtured them.” The evidence was sufficient to support the court’s finding that father’s care of the children nearly approximated mother’s in the qualitative sense, and we therefore discern no basis to disturb its conclusion that mother’s proposed relocation, combined with her disinclination to abide by father’s interest and rights to parent-child contact, would likely erode or destroy the children’s relationship with their father.
¶ 16. Mother further argues that “it is of no moment as to who was responsible for [father’s] reduced parent child contact” after she moved to Vergennes, relying on a comment to § 2.17(1) of the American Law Institute (ALI) Principles of the Law of Family Dissolution, which states that, where one parent has interfered with the other’s custodial time, “a parent who acquiesces in the new arrangements cannot later rely on parental prerogatives the parent did not value highly enough to protect.” ALI Principles of the Law of Family Dissolution § 2.17(1) cmt. b (2002). Here, as noted, the court acknowledged that father’s contact with the children decreased since mother’s move to Vergennes, but found that mother was partly to blame by interfering with father’s visitation. Nothing indicates, however, that father “acquiesced” to mother’s conduct. Accordingly, the claim does not undermine the court’s finding that the proposed relocation would significantly impair father’s relationship with the children.
¶ 17. Mother also appears to take issue with the court’s finding that the distance and duration of the proposed relocation would be substantial. Mother asserts that the finding is “speculative at best” because her husband had not, as of the date of the hearing, -received his transfer orders. Mother stated in her supplemental affidavit, however, that reassignment orders were imminent, and testified at the hearing in August 2005 that January 2006 was the “absolute end date” for her husband’s assignment to Vermont. Wife’s husband also testified that he could receive orders to relocate at any time, possibly to Washington state, Colorado, Georgia, or North Carolina, and that there was virtually no possibility of being reassigned to Vermont. Thus, the evidence does not support mother’s assertion that the court’s findings about relocation were speculative.
¶ 18. Finally in this regard, mother claims the evidence refuted the court’s finding that the alternative visitation schedule necessitated by mother’s relocation would significantly affect father’s relationship with the children. In support, mother cites father’s testimony that he *493remained committed to staying involved with the children even if it meant he had to fly long distances, as well as the testimony of the children’s paternal grandmother that, while she did not enjoy flying,she would endeavor to drive to see the children if they relocated to a state not too distant from Vermont. While these statements attest to the father’s commitment to maintaining contact with the children wherever they resided, they do not undermine the court’s finding that a relocation would significantly impair father’s ability to exercise existing custodial responsibilities, particularly considering mother’s past refusal of father’s visitation rights and her continued reluctance to fully accept same as suggested by her lack of candor to the court in misreporting her probability for relocation.
¶ 19. Mother’s second general claim is that the court misapplied the statutory factors governing the best interests of the children. In particular, mother contends the court failed to accord the quality of her relationship with the children the “great weight” to which she was entitled as their primary caretaking parent under Harris v. Harris, 149 Vt. 410, 418, 546 A.2d 208, 214 (1988) (holding that where one parent is established as the primary caretaker, “this factor should be entitled to great weight unless the primary custodian is unfit.”). This factor’s “great weight,” however, is not necessarily overwhelming weight, as Harris goes on to observe that “[t]he exact weight cannot be determined unless there is evidence of the likely effect of the change of custodian on the child. In the absence of such evidence, the court should ordinarily find that the child should remain with the primary custodian parent if that parent is fit.” Id. at 418-19, 546 A.2d at 214. The record here is replete with evidence and findings by the court that transferring custody to father would more likely preserve the father-child relationship, and so preserve the children’s relationship with both parents, would more likely promote visitation between the children and noncustodial parent, would be less likely to expose the children to parental disparagement and alienation, and would more likely preserve and maintain the children’s beneficial relationships with community, friends and family. The beneficial qualities of mother’s caretaking relationship with the children were tempered by her willingness to sacrifice the children’s beneficial relationship with their father for her husband’s career when, at the same time, she could not be relied upon to observe the father’s visitation rights.
¶ 20. The great weight of mother’s primary and beneficial custodianship was overcome, in the court’s view, by the risk of destruction to their relationship with father and by the accumulated weight of other *494factors favoring a change of custody to preserve the children’s relationships with both parents and minimize disruption to their stable relationships to family, Mends, home and community. As noted earlier, the court found — based on credible evidence — that father’s involvement in caretaking was nearly that of mother’s, and that mother’s “primary” status was maintained, in part, by denying father visitation once he could no longer pick up the children at day care. Thus, the evidence supported the court’s characterization of a custodial change in this case as a less-than-extreme result warranted by the best interests of the children. See Hawkes, 2005 VT 57, ¶ 12 (reaffirming earlier holdings that, when parties’ actual parenting arrangements are shared, practicalities of relocation may often necessitate a change of custody). That the evidence could have been weighed or balanced differently towards a different result does not render the court’s opposite conclusions an abuse of discretion. See Chick v. Chick, 2004 VT 7, ¶ 10, 176 Vt. 580, 844 A.2d 747 (mem.) (in evaluating best-interest factors under § 665(b), “[w]e afford the trial court wide discretion ... to assess the credibility of witnesses and weigh the evidence”). Accordingly, we find no merit to the claim that the court applied an incorrect standard or failed to defer adequately to mother’s role as the primary care provider.
¶21. Mother next contends the court improperly substituted its judgment for mother’s in expressing its reservations about the children being subject to “repeated moves” due to future military reassignments. The court opined that such moves were “unlikely to benefit [the children] in any significant way and may be severely detrimental.” The court’s comment about lack of benefit was without evident foundation. Nothing suggested that these children, or children in military families, or “corporate families” for that matter, expecting to move more frequently than others, do not benefit from cyclical relocation. Erroneous or unsupported findings do not require reversal, however, unless they are shown to have been prejudicial. Lyddy v. Lyddy, 173 Vt. 493, 496-97, 787 A.2d 506, 512 (2001) (mem.) (holding that inaccurate findings did not require reversal where “they were not controlling with respect to the court’s ultimate decision to award custody to mother”); Myott v. Myott, 149 Vt. 573, 577, 547 A.2d 1336, 1339 (1988) (party alleging error has burden of showing that he or she was prejudiced thereby).
¶ 22. The court invoked its concern several times over effects on the children of moving every three years far from father and their surroundings. Criticizing this concern as the family court simply substi*495tuting its “value judgment” for the mother’s, post, ¶ 34, the dissent ignores the more complicating factor of mother’s demonstrated reluctance to honor father’s visitation rights and her lack of interest in maintaining the children’s relationship with father. Reading the family-court’s decision in its entirety, however, leaves no doubt that the court’s award of custody to father was not based on a belief that cyclical relocation was “severely detrimental” per se, as opposed to being severely detrimental because of the particular surrounding circumstances in this case. Rather, the court incorporated its reservations about repetitive relocation in the context of its other findings, supported by the evidence, that the children stood to lose their stable relationship with family, friends, school and community here, as well as the relationship with their father due to mother’s proven reluctance to foster it.2
¶ 23. The decisive factor was not, as seen by the dissent, the frequency of moving, but the court’s concern that mother could not be relied upon to abide by a visitation order and that distant relocations would aggravate, rather than mitigate, that situation. The court’s reference to repeated moves was part and parcel of its overall conclusion that continued custody with mother was more likely to disrupt, if not destroy, the children’s relationship with father. This conclusion was supported by the evidence of mother’s noncompliant attitude towards visitation, her disregard for the children’s relationship with father and the distance of her expected moves. These expected detrimental effects, and not the lack of benefit, appeared to drive the court’s conclusions relative to future moves, so that mother was not prejudiced by the erroneous characterization of repeated relocations as “unlikely to benefit [the children] in any significant way.”
¶ 24. Relocation, by itself, is no basis to reassign custody. In this case, however, when combined with disruption of the children’s stability and the likely substantial, if not total, loss of relationship with their father, the anticipated moves by mother were fairly considered. That repetitive relocation must be balanced against an arguably more stable “quality of the child’s adjustment to ... present housing, school and community,” 15 V.S.A. § 665(b)(4), the child’s established relation*496ships with father and other significant family and friends, id. § 665(b)(7), leavened, or not, by the parents’ relationship with one another, id. § 665(b)(5), as well as “the quality of the child’s relationship with the primary care provider,” id. § 665(b)(6), are all a function of the statute and not merely the court’s predilection. Likewise, the court’s weighing of mother’s decision to follow her husband’s career at the expense of the children’s relationship with their father is also a requirement of the statute’s mandate to consider the relative merits of the parents’ “ability and disposition ... to meet the child’s present and future developmental needs,” id. § 665(b)(3), as well as ‘Yoster a positive relationship” with the other parent. Id. § 665(b)(5).
¶ 25. Transfer of physical custody of the children to father was supported by the court’s findings and balancing of the statutory factors. Courts consider these factors to promote the legislative declaration that, upon divorce of parents, “it is in the best interests of their minor child to have the opportunity for maximum continuing physical and emotional contact with both parents.” Id. § 650.3 Boiled down, the court explained that after weighing the evidence and balancing the factors, father could be relied upon to maintain the children’s contact with the other parent, but mother could not be relied upon to do the same. Thus, custody with father was more likely to accomplish continuing maximum contact with both parents, while maintaining custody with mother was less likely to achieve that goal considering the risk, based on history, that even minimum contact with father would have withered on mother’s watch. Because the court’s findings, conclusions and exercise of discretion thereon were all *497tenable, at the least, “[w]e therefore think that no abuse of discretion appears.” Dyer v. Lalor, 94 Vt. 103, 117, 109 A. 30, 36 (1920).
¶ 26. That the dissent, or even this entire Court, might reach a different conclusion on the same facts does not mean that the family court abused its discretion. Id. at 116, 109 A. at 36. Discretion necessarily allows for a range of reaction, so long as it is founded, as it is here, on reasons supported by evidence. Reasonable judges can differ in their response, but a “difference in judicial opinion is not synonymous with abuse of judicial discretion.” Id. (quotations omitted); Honran v. Preferred Acc. Ins. Co. of N.Y., 109 Vt. 258, 269, 195 A. 253, 257 (1937), abrogated on other grounds by Coop. Fire Ins. Ass’n of Vt. v. White Caps, Inc., 166 Vt. 355, 694 A.2d 34 (1997).
¶ 27. Mother further contends that, in applying the best-intprests criteria, the court failed to consider testimony by the children’s current daycare provider concerning their positive transition to Vergennes, “unreasonably minimized” evidence that the children had formed a close relationship with mother’s husband and his daughter from a prior marriage, and erroneously equated the parties’ ability to meet the children’s needs despite evidence that father had not visited the children’s school or preschool in Vergennes. Although the argument overlooks substantial modifying evidence — including father’s testimony that he phoned his daughter’s school frequently and requested that all school notices and report cards be mailed to him — the claim at bottom goes to the weight to be accorded the evidence, a decision that lies within the trial court’s broad discretion. Chick, 2004 VT 7, ¶ 10. There is no basis upon which to conclude that the court abused this discretion here.
¶ 28. Mother also claims there was no evidence to support the court’s stated concern that she might deny or interfere with father’s visitation in the event of a significant relocation out of state. The finding was based on father’s testimony concerning specific incidents in which mother had denied, or made it difficult for him to exercise, his visitation in the past, and his additional testimony that she had threatened her own family with a denial of access to the children. Mother disputed the assertion, and cited evidence that she had recently cooperated with father in executing a modified visitation schedule for the summer of 2005. As noted, however, the trial court has considerable discretion to assess the credibility of witnesses and weigh the evidence, and we will not disturb its findings unless clearly erroneous. Id.; Sochin, 2004 VT 85, ¶ 10. Assessed in light of this standard, and given that mother was *498less than forthright in her previous sworn statement, the evidence, while not extensive, was sufficient to support the finding.
¶ 29. Finally in this regard, mother contends the court abused its discretion by admitting parol evidence to show that father’s motive in stipulating to an assignment to mother of his equity in the marital home was to ensure that mother could afford to keep the children in their own home in Morrisville. Mother failed to object to the testimony on this ground, and therefore failed to preserve the issue for review on appeal. In re Merritt, 2003 VT 84, ¶ 7, 175 Vt. 624, 833 A.2d 1278 (mem.).
¶ 30. Mother’s third, and final, general contention consists of nine separate trial court findings allegedly unsupported by the evidence. Several of these, including father’s substantial involvement in the children’s custodial care, have been previously addressed. As to the remainder, mother makes virtually no claim or showing that the alleged inaccuracies, whether considered singly or in combination, undermine the court’s ultimate decision to award custody to father. See Lyddy, 173 Vt. at 496, 787 A.2d at 512 (holding that inaccurate findings did not require reversal of judgment where father failed to demonstrate they affected “the court’s ultimate decision to award custody to mother”). We discern no basis to disturb the judgment.
Affirmed.
Father acknowledged that, during shopping visits, his girlfriend helped pick out clothes and shoes for his daughter, and that he was therefore unaware of his daughter’s shoe size. Contrary to mother’s assertion, however, we are not persuaded that such ignorance undermines the court’s finding concerning father’s extensive role in the care of the children.
The dissent’s claim that no evidence supported the family court’s conclusion that repeated relocation would be detrimental to the children, post, ¶ 34, fails to acknowledge as detrimental mother’s degradation of father’s visitation rights, her dishonesty in connection with her plans to move, and her unjustified estrangement of the children from their father.
The dissent contends it was error for the family court to accord some degree of preference to maintaining the children’s relationship with their father over the stepfather, when their relationship with the stepfather was also beneficial. Post, ¶ 41. We do not agree that consideration of father’s status must be limited, as urged by the dissent, to each child’s relationship to him and his capacity to “provide the child with love, affection and guidance” as outlined as one of the “best interests of the child” factors under 15 V.S.A. § 665(b)(1). This argument appeal's settled by the Legislature’s additional and explicit declaration of public policy in § 650 that, at the least, presumes continued maximum parent-child contact “is in the best interests” of the children, “unless direct physical harm or significant emotional harm to the child or parent is likely to result from such contact.” Id. (emphasis added). Neither type of harm was alleged here, and the family court was persuaded that the children’s continued contact with “both parents,” the ultimate legislative goal, was not reasonably likely if physical custody vested in mother.